Manufacture of containers for carbonic acid gas and the like, and product thereof



Dec. 31, 1935. D MAPES 2,026,133

MANUFACTURE OF CONTAINERS FOR CARBONIC ACID GAS AND THE LIKE, AND PRODUCT THEREOF Filed June 16, 1954 2 Sheets-Sheet 1 a/ fliui. ll/Ill INVZNTOR IATTORNE s Dec. 31, 1935. E' 2,026,133

MANUFACTURE OF CONTAINERS FOR GARBONIC ACID GAS AND THE LIKE, AND PRODUCT THEREOF Filed June 16, 1934 2 Sheets-Sheet 2 1/0, MIME Patented n... a1, 1935 PATENT OFFICE MANUFACTURE OF CONTAINERS FOR CAR- BONICACID GAS AND THE LIKE, AND

PRODUGT THEREOF Daniel Mapes, Upper Montclair, N. J., assignor to Walter Kidde & Company, Inc., New York, N. Y., a corporation of New York I Application-lune 16, 1934, Serial No. 730,860

22 Claims. (cl. 29-1482) The present application is a continuation in part of my application Serial No. 339,545, filed February 13, 1929.

It has long been realized that gas, such as carbonic acid gas, compressed under great pressure, perhaps as high or higher than nine hundred pounds, has great potential advantages for airplane purposes, particularly for fire extinguishing, for motor starting and for flotation if the plane descends upon water. The practical use of such gas in connection with airplanes has not been possible heretofore because of the great weight which it has been thought that the containers must have in' order that they may withg stand the great internal pressure and comply with the regulations-of the Interstate Commerce Commission. Heretofo're the containers have been formed as cylinders open at one end and closed at the other from plates or billets by successive drawing operations, the cylinders being subsequently closed-in or shaped at the open end to receive the coupling for the delivery pipe or nozzle. The result has been the production of a cylindrical container of great and unnecessary thickness-at its closed end, of great and unnecessary thickness of its body wall, and of great thickness at its neck and shoulder end, where thickness is necessary to permit, without developing weakness, the shaping to receive the coupling and also to permit the stamping required by the regulations of the Interstate Commerce Commission. The thickness of the closed end andof the body wall has been much greater than that necessary to withstand the internal pressure and meet the requirements of the Interstate pommerce Commission. It has been this unnecessary thickness ofthe closed end and body wall, making most of the mass of the container, which has given such weight that it has not been practicable to use such containers for airplanes.

It has been the object of the present invention to make possible the production of such containers which shall have the necessary thickness and strength at the shoulder end and shall have else- 45 where no more thickness than is necessary.

In accordance with one modification of the invention, the formation of the container is proceeded with in the usual manner, whether from a plate or a billet, until there has been formed a 50 cylinder closed at one end and open at the other and of uniform diameter, both internally and externally, from the closed end to the open end.

Then, by machining, the thickness of thebody wall, to a circumferential line near the open end,

"55 is reduced, but without substantially reducing thethickness of the portion beyond that line, or, in any event, leaving suificient thickness beyond said line to permit proper closing-in of the container. If desirable for any reason the cylinder may also be machined internally. Then the portion be- 5 yond the circumferential line is closed-in without reducing its thickness and the neck on the shoulder is threaded andfinished in the usual manner.

In accordance with another modification of the 10 ner both with respect to each other and with respect to the closing-inoperation.

In accordance with a still further modification of the invention, in which the machining opera- 25 tions are also carried out, in part at least,-after the closing-in operation has been eifected, the thickness of the shoulder and itself is reduced to a predetermined thickness so that no unnecessary weight is retained at this point.

It is also within the scope of the invention-to apply the method thereof not only to a cylinder which is closed-in at one end only, but to cylinders having the other end or ends similarly formed, or formed in any other desired fashion. 35

Further modifications and variations of the invention will be apparent as the description proceeds with reference to the accompanying drawings, in which:

Figure 1 is a view in longitudinal se tion of a 40 partly formed container. 7

Figures 2 and 3 are similar views illustrating successive steps in the forming-of the container.

Figures 2a and 2b are views similar to Figure 2 illustrating modified steps in the transformation of the container of Figure 1- into the con-,- tainer of Figure 3.

Figure 4 is a similar view of a completed containera i Figure 5 is a view in lonigtudinal section of a cylinder open at each end from which a container is to be formed in accordance with a further process of the present invention.

Figure 6 is a similar view of the cylinder of Figure v5 after the ends thereof have been closed in. 5

Figure 7 is a view similar to Figure 6 showing the cylinder having its ends tapped and indicating machining operations to bring it to. a desired weight.

Figure 8 is a view in longitudinal section of an open ended cylinder having the ends thereof of a thickness permitting of a closing-in operation in accordance with a still further modification of drawings, a cylinder a closed at one end, as at b, and open at the other end, as at c, and of substantially uniform diameter from the closed end to the open end. In this condition the cylinder has a thickness at its closed end and in its side wall materially in excess of that required to enable it to resist the internal pressure to which it is subsequently subjected and of the requirements of the Interstate Commerce Commission.

Such unnecessary end and-body wall thickness gives the weight which practically prevents the use of thefinished container on an airplane. The next step in the manufacture is to reduce externally the thickness of the cylinder from and including the closed end b to a circumferential line, indicated at a near the open end of the cylinder, but without substantially reducing the thickness from that line to the open end, or, in any event, leaving sumcient thickness beyond said line to permit proper closing in of the container. It is not desirable that there shall be an abrupt shoulder between the reduced portion and the unreduced end portion and the reduction is therefore accomplished somewhat gradually, as indicated in Figure 2. It will be understood, therefore, that the circumferential line referred to is ,not precisely located as a mathematical line but is rather a band. This reduction of the cylinder externally is accomplished by machining.

The term machining consists of .any material-removing operation such as cutting, abrading, turning, grinding, and the like. If desired for any reason the cylinder may also be machined internally, care being taken to avoid undue reduction of the thickness of the body wall. The sequence of the machining steps may, of course, be varied, either the interior or the exterior of the cylinders being machined first without affecting the product and method outlined herein. When the cylinder has been formed as thusdescribed it is closed-in in any suitable manner, as indicated at d in Figure 3. Such closing-in efiects no reduction in wall thickness, but rather, it may be, a slight thickening. At all events a suiiicient body of metal is provided in this relatively short portion of the cylinder to give the required strength and to permit the stamping which the regulations of the Interstate Commerce Commission require. The closing-in operation naturally leaves an uneven central opening bounded by 'faultymeta], but the provision by this invention of the necessary thickness of metal at this point enables the 'faulty metal to be machined out. The end of the neck is then squared off, as indicated at d in Figure 4, and is threaded internally, as indihave eated at d to receive the coupling for the delivery pipe or nozzle and valve which must be secured to the container for the convenient discharge of the contents of the container. While the required strength of the container at the open end is thus retained, it will be obvious that the weight of the container is brought within practicable limits by the removal of the unnecessary mass of metal of the body and at'the closed end of the container. 10

It will be obvious that the cylinder of Figure 1 may be machined internally to leave the desired thickened end portion equally as well as it may be machined externally. 1

It will be obvious that the cylinder, as shown in Figure 1, may be produced in any convenient manner and likewise the reduction of the thickness of the body wall of the container may be effected by any convenient and suitable means.

Moreover, a cylinder closed at one end and open at the other end may be formed as already described in connection with Figure 1, the next step in the manufacture being to machine the cylinder internally, as shown in Figure 2a. The

cylinder is then closed-in in any suitable manner, as indicated at d in Figure 2b. If desired for any reason the cylinder may also be machined Figure 4 again shows a completed container as produced in accordance with the modified method herein described.

Referring now to Figure 5, the cylinder I may 85 have a wall thickness equal to the predetermined wall thickness of a finished container or such thickness may be greater than such predetermined wall thickness of a finished container. In the former case the bringing of the wall to the required thickness may be eifected in any suitable manner. The ends of the cylinder I are closed in any desired manner as for instance by a spinning-in operation, to form a container as shown in Figure 6 having closed ends 2 and 3. After the closing-in operation each end of the cylinder may be tapped as at 4 to receive a valve or plug or the like.

The closing of theends of the cylinder results in the ends 2 and 3 of the cylinder being of greater thickness than the cylindrical walls of the cylinder, as clearly shown in Figure 6, and possibly of greater thickness than. necessary to withstand the internal pressure and to permit the regulation stampings. Owing to this extra thickness of the cylinder at such parts there will be unnecessary weight at the ends of the cylinder and according to the present invention, after the closing of the ends of the cylinder, a part or parts of the cylinder having extra weight are re- 6 duced in thickness by machining.

If the cylindrical wall of the cylinder is of greater weight than necessary, such wall, after the closing of the end of the cylinder, is reduced in thickness by machining to the desired amount,

.der are reduced by machining operations taking oi! excess metal and I from the closed ends of the cylinder up to the dotted lines 6 and 8, respectiv ly- Referring to Figures 8 to of the drawings,

the open ended cylinder shown in Figure 8 is illustrated as having received a preliminary.

machining operation reducing the thickness of the'cylindrical wall intermediate the lines or bands 9 and II, spaced respectively from the ends of the cylinder, by an operation such as for instance a machining operation as described in connection with Figure 2 of the drawings, leaving the ends of the cylinder of sufiicient thickness to permit of closing-in operations.

. It will be appreciated however that the whole cylinder may have a wall thickness corresponding to the thickness of the ends of the cylinder illustrated in Figure 8, or that the preliminary machining operation on the cylinder intermediate its ends may be eifected by machining the internal surface of the cylinder.

.JI'he cylinder such as illustrated in Figure 8 has its ends closed in to form a container such as that illustrated in Figure 9. After the closingin operation the finishing of the ends of the cylinder may be effected to provide tapped openings II and I2, as illustrated in Figure 10, for the reception of a valve or plug onthe like.

After the closing-in operation the finishing of the cylinder is effected by machining parts thereof, such as the ends of the cylinder, which are of a thickness greater than necessary.- The -machining of the ends may be eifected by internal machining by means of expanding tools suitable for the purpose as indicated at the left hand side of Figure 10in which the metal IS on theinside end of the cylinder is removed by the aforesaid machining operation up to the line I4 in this, figure. If desired the reducing may be,

effected by external machining on the outer face of the end of the cylinder or both internal and external machining may be effected as indicated at the right hand end of the cylinder illustrated in Figure 4.10, in which the internal and external metal I5 is removed by internal and external machining operations, the internal machining removing metal from the inner face up to the line Ii of Figure 10 and-the external machining removing metal fmm the outer face of the end of the cylinder up to the line H.

Itwill be appreciated that the description of the forming of the container according to Figure 10 of the drawings is given with respect to a containerin which the wall thickness thereof has been previously reduced to the desired amount, the machining operations applied to the ends of the container being in such case for the purpose of ensuring the lightest cylinder of the required strength which may be obtained. If the wall of the cylinder is not reduced to the desired amount ders in-which a preliminary machining operation is followed by a closing operation, and then by a final machining operation. y

It will of course beappreciated that the ends of the containers in accordance with the present invention are preferably substantially hemispher- V ical in shape, it being well known that a spherical container of given wall thickness is twice as strong as a cylindrical container, and from this consideration it will also be apparent that the method of the present invention in certain of its 5 aspects is applicable to the formation" ofspherical containers of minimum weight, so thatthe invention is not to be limited except as defined in the appended claims.

I claim as my invention:

1. The method of making cylindrical metal containers for carbonic acid gas and the like which consists in forming a cylinder open at one end and closed at the other and of substantially uniform fandexcessive wall thickness from the closed end to the open end, reducing by machining externally thethickness of thevcylinder from V the closed'end to a circumferential line near the open end without substantially reducing the thickness from that line to the open end and machining} the cylinder internally to a predetermined thickness, closing-in the cylinder from that line to the open end, and finishing the open end and closed-in portion of the cylinder;

2. The method of making cylindrical metal containers for carbonic acid gas and the likewith at least one end closed-in which consists in forming a cylinder of substantially uniform and excessive ,wall thickness from one end to another, reducing by machining externally' the thickness of the cylinder from a circumferential line near an endto be closed-in toward another end without substantially reducing the thickness from the said circumferential line to said end to be closed-in and machining the cylinder inter nally to a predetermined thickness, closing-in the cylinder from adjacent said circumferential line to said end to be closed-in, and finishing said necked-in portion of the cylinder.

' 3. The method of making'high pressure cylin- 40 l 'consists in forming a cylinder of substantially uniform but greater than necessary wall thickness from one end to another, reducing by machining externally the 'thickness of the cylinder from a circumferential line near an end to be closed-in toward another end leavingsumcient thickness from said line to said end to be closed-in .topermit proper closing-in and machining the cylinder internally to a predetermined thickness, and closing-in the cylinder from adjacent said circumferential line to said end to be closed in.

4. The method of making high pressure cylindrical metal containers for carbonic'acid gas and the like with at least one end closed-in which consists in forming a cylinder with suflicient thickness at an end to be closed-in to permit proper closing-in and of a wall thickn ssreater than necessary to withstand the high-pressure, reducing the thickness of the cylinder by machining a surface thereof from-a circumferential line near 'an end to be closedin toward another end leaving suiiicient thickness from said line to said end to be closed-in to permit proper, closing-in and machining the opposite surface of the cylinder to a predetermined wall thickness, andclosing-in the cylinder from' adjacent said circumferential line to said end to be closed-in.

5. The method of producing a high pressure cylindrical metal containerwith a relatively thick walled shoulder, a closed bottom and a thin side wall of substantially minimum thickness towithstand a predetermined high pressure from a tube open at at least one end, by machining at'ieast 7s a portion of at least oneoof the surfacesof the side wall of the tube and closing-in an open end of the tube.

6. The method of making high pressure cylindrical metal containers for carbonic acid gas and the like with at least one end closed-in which consists in forming a cylinder with suflicient thickness at an end to be closed-in to permit closing-in and of a wall thickness greater than necessary to withstand the high pressure, reducing the thickness of the cylinder by machining a surface thereof leaving sufficient thickness at an end to be closed-in to permit proper closing-in, machining the'opposite surface of the cylinder to a predetermined substantially minimum wall thickness to withstand the high pressure, and closing-in the cylinder.

'7. The method of making high pressure cylindrical metal containers for carbonic acid gas and the like with at least one end closed-in which consists in .forming a cylinder with suflicient thickness at an end to be closed-in to permit proper closing-in and of a wall thickness greater than necessary to withstand the high pressure, and reducing the thickness of the cylinder by machining a surface thereof leaving sufficient thickness at an end to be closed-in to permit proper closingin and machining the opposite surface of the cylinder to a predetermined substantially minimum wall thickness to withstand the high pressure and closing in the cylinder. p

8. The method of producing a high pressure cylindrical metal container with a relatively thick walled shoulder and a thin side wall of substantially minimum thickness to withstand a predetermined high pressure from a tube open on at least one end, by machining at least a portion of at least one of the surfaces of the side wall of the tube and closing-in an open end of the at least one end, by machining at least a portion of the insideand outside surfaces of the side wall of the tube and closing in an open end of the tube.

10. The method of producing a high pressure cylindrical metal container with a relatively thick walled shoulder, a closed bottom and thin side walls from a tube closed on one end and open at the other, by machining at least a portion of at least one of the surfaces of the tube and-closingin the open end of the tube, the machining iri-v cluding the closed bottom end and the portion closed-in.

12 The method of producing a high-pressure cylindrical metal container with a relativelythick walled shoulder, a closed bottom and thin side walls from atube closed on one end and open at the other, by machining at least a portion of at least one of the surfaces of the tube and closin in the open end of the tube, the machining including the portion closed-in.

.13. The method of producing a. high pressure cylindrical metal container with a relatively thick walled shoulder, a closed bottom and thin side wall of substantially minimum thickness to withstand a predetermined high pressure, from a tube closed on one end and open at the other, by ma- 5 chining at least a portion of at least one of the surfaces of the tube and closing-in the open end of the tube.

14. The method of making high pressure cylindrical metal containers for carbonic acid gas and 10 the like with at least one end closed-in which consists in forming a cylinder with suflicient thickness at an end to be closed-in to permit proper closingin and of a wall thickness greater than necessary to withstand the high pressure, reducing the thicklb ness of the cylinder by machining a surface thereof from a circumferential line near an end to be closed-in toward another end leaving sumclent thickness from said line to said end to be closed-in to permit proper closing-in, closing-in 20 the cylinder from adjacent said circumferential line to said end to be closed-in, and machining the opposite surface of the cylinder to a predetermined wall thickness.

15. The method of making high pressure cylindrical metal containers for carbonic acid gas and the like with at least one end closed-in which consists in forming a cylinder with sufficient thickness'at an end to be closed-in to permit proper closing-in and of a wall thickness greater than necessary to withstand the high pressure, reducing the thickness of the cylinder by machining a surface thereof leaving suflicient thickness at an end to be closed-in to permit proper closing-in, closing-in the cylinder, and machining the opposite surface of the cylinder 'to a predetermined wall thickness. j

16. The method of producing a high pressure cylindrical metal container with a-relatively thick walled shoulder and a thin side wall of substan- 40 tially minimum thickness to withstand a predetermined high pressure from a tube open on at least one end, by closing-in an open end of the tube to form a shoulder having a substantially hemispherical contour, and machining at least a portion of at least one of the surfaces of theshoulder of the resulting container.

17. The method of making high pressure cylindrical metal containers for. carbonic acid gas and the like with at least one end closed-in which consists in forming a cylinder with sufficient thickness at an end to be closed-in to permit proper closing-in and of a wall thickness greater than necessary to withstand the high pressure, closingin the cylinder, and then reducing the thickness of the cylinderby machining first one surface thereof and then the other surface thereof to a predetermined minimum thickness to withstand apredetermined high pressure.

' 18. The method of producing a high pressure cylindrical metal container for carbonic acid gas and the like with a relatively thick walled shoulder, a closed bottom and a thin side wall of substantially minimum thickness to withstand a predetermined high pressure from a tube open on at 5 least one end, by machining at least a portion of at least one of the surfaces of the tube, closing-in an open end of the tube, and machining at least a portion of the other surface of the resulting container.

19. The method of producing a high pressure cylindrical metal container with a relatively thick walled shoulder, a closed bottom and thin side walls of substantially minimum thickness to with-- stand a predetermined high pressure from a tube 7 ..clo sed on one end and open at the other, by combined machining and closing-in operations, the

walled shoulder and thin side walls of substantial ly minimum thickness to withstand a predetermined high pressure from a tube open onat least one end, by combined machining and closing-in operations, the machining including at least. a portion of one of the surfaces of the structure exclusive of the usual machining required to adapt the container for the reception of a valve or plug or the like, and the amount of said machining being such asto cause the machined walls to be of a minimum thickness to withstand a predetermined high pressure. I

21. As an article of manufacture a machined high pressure cylindrical metal container with relatively thick walled shoulder and thin side walls of substantially minimum thickness to withstand a predetermined high pressure made from a tube open on at least one end, by combined machining and closing-in operations, the machining including at least a portion of one of the surfaces of the structure exclusive of the usual machining required to adapt the container for the reception of a valve or plug or the like, and the amount of said machining being such as to cause the ma- 10 chined walls to be of a minimum thickness to I withstand a predetermined high pressure.

22. As an article of manufacture a machined high pressure cylindrical metal container with relatively thick walled shoulder and thin side walls 15 in an open end of the tube, and machining a por- Q0 tion of the outer surface of the resulting container.

DANIEL MAPE S. 

